Correct Answer - A
We have,
Total number of elementary events
=
6
×
6
×
6
=
216
=
.
Clearly, the second number has to be greater than unity. If the second number is
i
(
i
>
1
)
i
, then the first can be chosen in (i-1) ways and the third (6-i) ways. So, three numbers can be chosen in
(
i
−
1
)
×
(
1
(
6
−
i
)
(
ways. But, the second number can vary from 2 to 5. Therefore,
favourable number of elementary events
=
5
∑
i
=
2
(
i
−
1
)
(
6
−
i
)
=
1
×
4
+
2
×
3
+
3
×
2
+
4
×
1
=
20
=
Hence, required probability
=
20
216
=
5
54
=